• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.127-129
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• 1996

A 3-dimensional analysis is desired for a magnet of magnetically levitated vehicle because the geometrical shape of the magnet is complicated and nonsymmetric. A FEM package of FLUX3D is used to analyze the characteristic of the magnet. Various quantities could be observed like levitation force, flux density distribution along the air gap, edge and fringing effect, leakage flux pattern, etc. The simulation results from FLUX3D are compared with those of 2-D analysis and test results. There are a little difference between results due to the boundary conditions and magnetized B-H curve of the core.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.28-31
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• 1997

Experiments and design efforts have been made to improve performance of the levitation magnet. One pole of the pair-magnet is manufactured as a solid core without stagger and its test result gives a 5 % increment of levitation force. One effort is to make molding coil to protect it from vibration and precifitation due to outdoor usage. In addition, a permeant magnet embedded type has been designed and analyzed by using FEM program.

• 대한전기학회논문지
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• 제41권1호
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• pp.18-23
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• 1992

Magnet core and rail of a magnetically levitated vehicle are usually made of highly conductive materials. Accordingly, eddy currents are induced in those members. Eddy currents often lead to a decrement of levitation and guidance force. This paper has calculated the decrement of both forces due to eddy current generated by magnet's vertical and lateral motion. U-shaped electromagnet and rail were chosen as amodel of 2D finite element analysis. Calculated results proved that both forces dropped significantly at high speed. Consequently, effects of eddy current should be considered in designing the magnet and control system.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1277-1282
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• 2014

Concentrated flux interior permanent magnet (CFIPM) motors have the advantage that their utilization of flux linkage is more efficient than that of general IPM motors and CFIPM motors are suitable for washing machine motors, which demand low-speed, high-torque specifications. However, low efficiency occurs in the low-speed high-torque mode considering the high-speed operation for spin mode. This paper proposes a magnet overhang structure between the rotor core that reduces leakage flux and improves efficiency for a CFIPM in wash mode. Optimization of the 3D design of magnet overhang structures is performed to improve the efficiency with the same quantity of permanent magnets. The validity of the optimal design is experimentally verified through the fabrication of prototypes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.58-62
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• 2006

The purpose of this paper is characteristic analysis of permanent magnet generator (PMG) for automatic voltage regulator (AVR)power of brush less synchronous generator. However, this PMG has a spoke type permanent magnet rotor with large overhang for high power density, characteristic analysis considering concentration effect of air-gap flux density due to the overhang should be performed. 30 transient finite element method (FEM)analysis is good solution for overhang parameter, but this method needs too much calculation time. In this paper, we examined the overhang effects based on overhang length and material of rotor core by using 20 and 30 static FEM analysis, and proposed 20 dynamic FEA model considering overhang parameter which gives good and rapid results. The proposed method is verified by the test results of no load, load and short circuit test.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.942-949
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• 2014

We studied about the rotor design change using a Ferrite ring magnet to reduce material cost in the condition of the same stator core design. However, this design direction has many weak points such as the decrease of BEMF, the low maximum output, the irreversible demagnetization characteristics of a permanent magnet and so on. In order to mitigate such disadvantages, an optimization design of the BLDC motor has been developed by changing each design parameter and by improving the electromagnetic structure. In the proposed water pump SPM BLDC motor using Ferrite magnet, the outer and inner diameter of stator is fixed to the value of the conventional IPM BLDC motor using Nd-Fe-B magnet. The design specification requirements should be satisfied with the same output power and efficiency characteristics in the same dimension. As a result of this study, the design comparison results considering driving performances and material cost are represented. Through the actual experiment with the prototype of the designed motor, the simulations results are verified.

• 조명전기설비학회논문지
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• 제27권9호
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• pp.62-73
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• 2013

In this paper, a new linear synchronous motor - permanent magnet double-sided synchronous motor with perpendicular arrangement (PMDLSM), was proposed. It was designed to account for the drawbacks of conventional linear motors, such as the normal force and end effects. The detent force and the thrust were analyzed for different combinations of primary core modules and magnet poles of the machine, and the optimum combination was made. The characteristics of the perpendicular PMDLSM were analyzed by finite element method, and the experiments agreed well with the analysis.

• Journal of Magnetics
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• 제20권4호
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• pp.444-449
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• 2015

Soft magnetic composites (SMCs) are especially suitable for the construction of low-cost, high-performance motors with 3-D magnetic fields. The main advantages of SMCs is that the iron particles are insulated by the surface coating and adhesive used for composite bonding, the eddy-current loss is much lower than that in laminated steels, especially at higher frequencies, and the hysteresis loss becomes the dominant component of core losses. These properties enable machines to operate at higher frequencies, resulting in reduced machine size and weight. In this paper, 3-D topologies are proposed that enable the application of SMCs to effectively reduce losses in high-speed permanent magnet (PM) motors. In addition, the electromagnetic field characteristics of the motor topologies are evaluated and compared using a non-linear finite element method (FEM) based on 3-D numerical analysis, and the feasibility of the motor designs is validated.

• Journal of Magnetics
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• 제16권1호
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• pp.74-76
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• 2011

Interior permanent-magnet synchronous motors (IPMSMs) produce both magnetic and reluctance torques. The reluctance torque is due to the difference between the d- and q-axis inductances based on the geometric rotor structure. The steady-state performance analysis and precise control of the IPMSMs greatly depend on the accurate determination of the parameters. The three essential parameters of the IPMSMs are the armature flux linkage of the permanent magnet, the d-axis inductance, and the q-axis inductance. In the basic design step of an IPMSM, the inductance parameters are very important for determining the motor characteristics, such as the input voltage, torque, and efficiency. Thus, it is very important to accurately estimate the values of the motor inductances. The inductance parameters of IPMSMs have nonlinear characteristics along the magnet size because the iron core is saturated by the magnet and armature reaction fluxes. In this study, the inductance parameters were calculated using both the magnetic-equivalent-circuit method and the finite-element method (FEM). Then the calculated parameters were compensated by the saturation coefficient function, which was also calculated via the magnetic-equivalent-circuit method and FEM.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1169-1170
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• 2006

We made a high-speed motor and a DC brush-less motor for factory automation (FA) to investigate applicability of powder magnetic core to motor application, and compared those performances with the similar motors having conventional electro magnetic steel core. Permeability and saturated magnetization of powder magnetic core are less than those of elect romagnetic steel core, however output performances of each core motor are almost the same. The FA motor with powder magnetic core using three-dimensional magnetic circuit showed higher torque than the same volume motor with electromag netic steel core.